but you need to have a good grinder to avoid the "sludge." A whirring blade grinder isn't very consistent and results in a mixture of "boulders" and "dust." It's the dust that gets past the metal filter and creates the sludge, the sediment that turns to mud at the bottom of the cup. A conical burr mill grinder will produce an even, consistent grind. Once you have a decent grinder, then it's time to play with the grind. You want it coarser than that for drip filter but not any coarser than necessary as too coarse a grind with inhibit complete extraction. Coarse enough so that it doesn't clog the filter and the plunger is still easy to press down.
The reason I like the French Press is that I can control the steep time where with a paper filter it's just a function of gravity and paper thickness. The Press also allows a lot of the oil and flavonoids that paper filters tend to block.
"Charbucks" is over-roasted. That's part of their brand identity so that you can walk into a Charbucks anywhere in the world and their coffee will taste the same. The roast overpowers the delicate flavors of the bean.
Myself, I prefer a medium roast. There's more flavor and lighter roasts have more caffeine than darker roasts so I don't need to drink as much to get the same effect.